nrf52810 SPI anomaly - similar to errata [109]https://devzone.nordicsemi.com/f/nordic-q-a/54796/nrf52810-spi-anomaly---similar-to-errata-109I am dealing with a strange anomaly on the MOSI line of the SPI bus - sometimes, the first byte of a command 0x84 to the external SPI flash, I get this on the bus (~ 4 MHz SPI clock, sampled at 50 MHz): I may not pick the second pulse at all timesen-USTelligent Community 13Mon, 25 Nov 2019 16:55:21 GMTRE: nrf52810 SPI anomaly - similar to errata [109]https://devzone.nordicsemi.com/thread/221930?ContentTypeID=1Mon, 25 Nov 2019 16:55:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d7ad0984-608f-4a57-9dfc-a88c7afb6bc5MatevzB<p>You can close the ticket - the issue has been traced to SPI flash chip holding the MOSI line low. Although the SDI pin can be used as bidirectional pin, this should only apply after the first command byte after CS going low - it appears to be an undocumented &#39;feature&#39; for the SPI flash...</p><div style="clear:both;"></div>RE: nrf52810 SPI anomaly - similar to errata [109]https://devzone.nordicsemi.com/thread/221898?ContentTypeID=1Mon, 25 Nov 2019 14:53:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8e524341-caa8-4eb3-acc6-1e6c89b44130Jared<p>Hi,</p> <ul> <li>Are you using the development kit or a custom board? Could you share the design files if you use a custom board?</li> <li>Could you see if <a href="https://infocenter.nordicsemi.com/pdf/nRF52_PAN_109_add_v1.1.pdf">workaround 3.7 in the Errata workaround description</a> resolves the issue?</li> <li>How often do you see the spurious signals?</li> <li>If you&#39;re using the development kit, could you try changing the wire that you use for MOSI.</li> </ul> <p>regards</p> <p>Jared</p><div style="clear:both;"></div>RE: nrf52810 SPI anomaly - similar to errata [109]https://devzone.nordicsemi.com/thread/221721?ContentTypeID=1Sun, 24 Nov 2019 21:09:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0fdc75ad-99af-461b-ade0-932572b91508MatevzB<p>Additional data: removing sleep from the waiting loop doesn&#39;t improve on the issue. Moreover, spurious signals appear in other bytes (not only the first one).</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1574629839923v1.png" alt=" " /></p><div style="clear:both;"></div>